Electrical distribution system



June 1942- A. A. TOG-ESEN ETAL ELECTRICAL DISTRIBUTION SYSTEM 5Sheets-Sheet 1 Filed June 12, 1941 ll l [IIIIIII lillll DN E P b J fil ll llflnfllllw lflmlllfillllllllllll MWMIIIII an l unua I l June 23,1942.

A. A. TOGESEN EIAL' ELECTRICAL DISTRIBUTION SYSTEM Filed June 12, 1941 5Sheets-Sheet 2 INVENTOR.

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A. A. TOGESEN ETAL 2,237,502 ELECTRICAL DISTRIBUTION SYSTEM Filed une12, 1941 5 Sheets-Sheet 5 in use with I Patented June 23, 1942 OFFICE'2,287,502 ELECTRICAL DISTRIBUTI ON SYSTEM Alva A. Togesen and L Company,Virginia awrence E. Fisher, Detroit, Mich., assignors to BulldogElectric.Products Detroit, Mich., a. corporation of West ApplicationJune 12, 1941, Serial No. 397,720

31 Claims.

This application relates to electrical distribution systems and moreparticularly to systems of the bus bar type.

Aims and objects of the invention disclosed herein will best beunderstood upon reference to the following detailed description,relating to the appended drawings. In these drawings:

' Figs. 1, 2 and 3 shows a unit length of bus duct oi the system in t pplan, side and end views respectively.

Fig. 4 is a diagrammatic ance with Fig. 3.

Fig. 5 is a similar flcation.

Figs. 6 and '7 illustrate arrangements for joining pairs of bus bars andfor providing tap-offs, in the system of Figs. 1 to 3.

Fig. 8 shows a duct seam in detail.

Figs. 9 and 10 show two different arrangements for joining bus bars endto end.

Fig. ll shows an arrangement for joining unit lengths of bus duct end toend, using bus bar joints of the type shown in Figs. 9 and 10.

Figs. 12 and 13 show two different arrangements for mounting bus bars induct.

Figs. 14 15 are plain and side views of an insulator support for threebus bars.

Figs. it; to ill show the support of Figs. 14-15 three differentrelative spacings of end view in accordview of a four-bus bar modifousbars.

Figs. 1% 26 for supporting bus bars in duct.

21 shows how bus bars may be supported by the barriers, rather by thecasing.

Detailed description 1 unit len th of bus duct disclosed in Figs. to endto another to at run. It consists of two long bus s of which the ductsections are the channels arranged edge to edge to form a with each edgeoutwardly flanged as at all, the olicnn ls projecting beyond one anotherends to pro-ode lap searl ,toints. Betweenthe channels thus closing themand isolating them from other, and disposed between the 29 joining b-ols22, (Fig. ii), is an insulation to means bich is in the form of twosheets of insulation, as shown, secured to the individually to formindividual closures for them. Bus bars 25 are within the channels.

An important feature of the show a modified arrangement system hereinshown is the novel inter-relation of bus bars,

so to be held in place by the cessible for a considerable reduction ofvoltage shown for example in Fig.3 and diagrammatically in Fig. 4.Referring particularly to Fig. 4, it will be seen that the duct thereinshown includes six bus bars of which the two bus bars A and A form onephase, B and B another phase and C and C a third phase. The bus bars areso arranged as to form pairs A-C', BA and CB', and the bus bars of apair are relatively close to each other. For example, bus A is veryclose to bus C, bus B is close to bus A, and bus C is close to bus B.

However, the pairs are relatively far apart. For example, the pair AB isfar from the pair AC and from the pair C--B'. Further, the conductorsare arranged in two definite and distinct groups, A B C, A 13 C (Fig.4), with each group including one conductor from each of three phases.

The fact that the bus bars within a pair are close to each other is to alarge extent respondrop in the system. The close spacing of the bus barshas been found efiective to reduce the reactance and bus bar systemshaving the bus bars close to each other can be considered to be of theLo-reactance type.

However, the provision of wide spaces between the pairs provides accessinto the duct between the pairs for joining or mounting or for any otherdesired purposes.

It has been considered that because the pairs are far apart, the systemherein shownmay well be considered as a parallel system of single phasedistribution and this analysis might be helpful here. For example thecurrent flow in bus A (Fig. 4) is equal in value and opposite in vectorrelation to that in bus C and that holds true of bus B vs. bus A and busC vs. This is a typical characteristic of single phase transmis sion andafiords a basis for our conclusion that.

distribution and a great advantage is obtained by the relatively closespacing within the pair.

Further, great spaces between the pairs provides a large air circulationarea, and makes it possible to have radiation of heat from the pairs.

The bus bars herein shown are thin and wide and this is also helpful inreducing losses parof the bus bars ticularly in the distribution ofalternating current.

The provision of closely spaced bus bars within the pairs, efiects areduction of the magnetic field and permits the use of steel for thecasing with no sacrifice of reactance drop, heretofore compensated forby the use of aluminum as part of the casing.

Fig. 5 shows a variation of the system. Whereas in Fig. 4. the bus ductis shown as including six bus bars arranged as indicated, the systemshown in Fig. 5 includes but four bus bars, two of which are of doublesize so as to form the equivalent of six bus bars and the arrangement ofbus bars consequently, following that of Fig. 4, permits all of thedesired results to be obtained with the use of but four bus bars, ratherthan with six. Thus bus bars A and A are merged into one, as are busbars B and B. Bus bars C and C are, of course, not merged in thearrangement shown.

Arrangements for tieing together bus bars are indicated in Fig. 6 wherethe bus bars are shown tied together by tie straps 29.

For tapping off at suitable points, the arrangement suggested by Fig. '7might well be employed. This arrangement includes straps 30 properlyconnected to the bus bars for tieing them together and having extensions3! projecting out of the duct for providing tapofi. I

Figs. 9-10 show a novel arrangement for providing end to end joints forbus bars which are separated by insulation barriers. Fig. 9 shows tworows ofbus bars 25 which form upper and lower rows of bus bars in asingle unit length of bus duct. These rows are to be joined relativelyend to end to other rows of bus bars, which also form upper and lowerrows of bus bars of another unit length of bus duct. Between each row ofbus bars is an insulation sheet, such as shown at 23. By offsetting theends of the bus bars or one row. as indicated, and by the proper use offiller pieces 33 of insulation, an efllcient and satisfactory and easilymanipulable joint is provided. Bolts 34 thread into the busbars toeffect the joint.

Fig. 10 shows a similar arrangement but employing two sheetscfinsulation 23-24 between the rows of bus bars in a unit-length of busduct. This arrangement eliminates the necessity for using the fillerpieces 33' and contemplates lapping of insulation sheets at a joint.

Fig. 11 shows how the arrangement of Fig. 10 is utilized in connectionwith the duct sections that cooperate with the bus bar sections to forma unit length of bus duct. 'The duct sections each comprise an upperchannel as well as a lower channel, with one of the channels projectingbeyond the other at an end as indicated, to form a lap scar! joint. Thejoining bolts 34 for Joining the bus bars; have their axes perpendicularto the meeting plane of the duct and this is parallel to the meetingplane of the bus bars: thus it is possible to move the end of one busduct length to another in the direction indicated by the arrows, whichis of convenience particularly in the event a long run of bus duct isbeing assembled where a unit length has one end anchored, while to theother end is being joined an end of a free unit length 0! bus duct.

Pedestal type insulators 50, disposed within and secured to transversestrips 50A, as shown in Figs. 12 or 13, for example, secured to the websII of the channels either by bolts 52, as in Fig. 12, or by welding, asshown in Fig. 13, receive screws 53 for mounting ,the bus bars 25, laidflat on the pedestals and disposed with their flat surfaces parallel toand close to the insulation barrier means 23-44.

Figs. 14 to 15 illustrate another form of insulator support for bus barsand Figs. 16 to 18, indicate its use. of a single bar or strap 60 ofinsulating material having two holes 6| between its ends for receivingbolts for securing it to a duct and having three holes 62 for receivingbolts which secure bus bars to the insulator. The spacing of the variousholes has been properly designed so as to enable the insulator to beused as a support for three different spacings of bus bars as shown inFigs. 16-18.

For example Fig. 16 shows an arrangement em ployed in a 2500 amp. busbar system where the center to center distance X between bus bars is 7inches. Fig. 17 shows an arrangement for a 1500 amp. bus bar systemwhere the distance 'X was 5 inches. Fig. 18 shows'an arrangement used ina 500 amp. system where thedistance X was 3 inches.

Figs. 19 and 20 show still another arrangement for supporting bus barsin duct. In this arrangement each support consists of two narrowchannels 63 telescoped on each other and extending across the duct forits full width and being secured to the duct by suitable screws.

Within the space between the channels are three insulation blocks 64 andabove these blocks are three pedestals each of which supports a bus bar.The supporting screws for the bus bars thread through thepedestals andinto the insulation blocks. these having nuts imbedded within them forreceiving the screws. On the other hand, the screws might well havetheir needs within the insulation blocks and their shanks threadedthrough the pedestals and into the bus bars.

Fig. 21 shows the bus bars supported by suitable screws from the barriersheets 23-44, rather than from the channels.

An important feature of the system herein shown is the ease of assemblyof the bus duct, both-from the point of view of assembling a unit lengthduring manufacture, and from the point of view of assembling unitlengths end to end to form an installation. It will be seen that the busduct as a whole is made up of unit lengths. Each unit length islongitudinally split to comprise separate and distinct individuallycomplete complementary bus duct sections, an upper one and a lower one,these being disposed alongside each other and interjoined at theirlongitudinally extending meeting edges or flanges. Each bus duct sectionof a unit length comprises a unit length of duct or channel, a unitlength of bus bar or bus bars, depending upon how many bus bars arewithin the duct, and its own individlral means for v supporting the busbar length or lengths in the duct lengths. free and independent of anypart oi the complementary bus duct sections. The construction is suchthat before two complementary bus duct sections are brought adjacenteach other and interjoined each bus duct section is complete with itsduct or channel, its bus bar or bus bars and its bus bar supportingmeans. The assembly of a unit length is completed simply by interjoiningthe bus duct sections.

Each bus duct section may be seen to comprise an open pan or channel ofU cross section whose open side is closed by its own individualinsulation closure. The closures of two pans or channels, thoughseparate and distinct and separately supported, are adjacent when thebus duct sections are interjoined and. each bus The insulator here shownconsists bar is thus disposed in a confined space between the bight ofits pan or channel and the insulation closure and each bus bar issupported by the pan or channel, rather than by the closure,

Now having described the bus duct system herein disclosed, referenceshould be had to the claims which follow for a determination of theinventions thereof.

We claim:

1. An electrical distribution system comprising an elongated distributormade up of lengths joined end to end, each length of distributorcomprising a casing made of elongated parts joined longitudinally onmeeting lines, with certain of the parts overlapping the others at oneend of the casing length and underlapping the others at the other end ofthe casing length, whereby casing lengths are joined end to end by scarflap joints, each length of distributor also comprising conductor lengthswithin the casing length and substantially coterminous therewith, theconductor lengths of one distributor length being arranged to lap overconductor lengths of another distributor length when the two distributorlengths are joined end to end, the lapping planes of the conductorlengths being parallel to the lapping planes of the casing lengths,whereby the conductor lengths and the casing length of a distributorlength may be tion for endto end joining to the corresponding parts ofan installed distributor length.

2. An electrical distribution system comprising an elongated distributormade up of lengths joined end to end, each length of distributorcomprising a casing made of elongated parts joined longitudinally onmeeting lines, with certain oi the parts overlapping the others at oneend of the casing length and underlapping the others at the other end ofthe casing length, whereby casing lengths are joined end to end byscarflap joints, each length of distributor also comprising conductor lengthswithin the casing length and substantially cotermincus therewith, theconductor lengths of one diatrib utor length being arranged to lap overcan ductor lengths of another distributor length when the twodistributor lengths are joined end to end, the lapping planes of theconductor being parallel to the lapping planes oi the casing lengths,whereby the conductor lengths and the casing length of a distributorlength may he moved simultaneously and in the d tion for end to endjoining to the 3 ing parts of an installed distributor length, being, ineach casing length, two rows or conductor lengths, a plurality to eachrow, with the plane or each row being parallel to the said ing planes.

3. An electrical distribution system cor an elongated distributor madeup o: joined end to end, each length or? diets comprising a casing madeof elongated joined longitudinally on meeting lines, as tain of theparts overlapping the othe end of the casing length and underli othersat the other end of the cast whereby casing lengths are joined end e byscarf lap joints, each length of also comprising conductor lengths lcasing length and substantially cot ions therewith, the conductorlengths of one distrib utor length being arranged to lap over condo-ctor lengths of another distributor length when the two distributorlengths are joined end to ,allel to the said meeting planes,

end, the lapping planes of the conductor lengths being parallel to thelapping planes of the cusing lengths, whereby the conductor lengths andthe casing length of a distributor length may be moved simultaneouslyand in the same direction for end to end joining to the correspondingparts of an installed distributor length, the parts of each casinglength comprising two identical channels arranged with their open sidesadjacent, one offset longitudinally with respect to the other.

4. An electrical distribution system comprising an elongated distributormade up 01 lengths joined end to end, each length of distributorcomprising a casing made of elongated Darts joined longitudinally onmeeting lines, with certain of the parts overlapping the others at oneend of the casing length and underlapping the others at the other end ofthe casing length, whereby casing lengths are joined end to end by scarflap joints, each length of distributor also comprising conductor lengthswithin the casing length and substantially coterminous therewith, theconductor lengths of one distributor length being arranged to lap overconductor lengths of another distributor length when the two distributorlengths are joined end to end, the lapping planes of the conductorlengths being parallel to the lapping planes of the casing lengths,whereby the conductor lengths and the casing length of a distributorlength may be moved simultaneously and in-the same direction for end toend joining to the corresponding parts of an installed distributorlength, the parts of each casing length comprising two identicalchannels arranged with their open sides adjacent, one otisetlongitudinally with respect to the other, there being, ln each casinglength, two rows of conductor lengths, a plurality to each row, with theplane of each row being pareach channel containing one of the two rowsof conductor lengths, with the lapping part of each conductor lengthbeing between the adjacent ends of the two channels of a casing length.

In a polyphase distribution system, a source oi polyphase alternatingcurrent, a plurality oi wide thin conductors connected thereto andarranged in remotely spaced deilnite and distinct pairs, each com risingtwo evenly and closely spaced eon-doctors of different phases, ar- Wicleface near wide face, each phase comprhing we conductors of differentpairs, the relatl r arrangement of and the spacing between the trioconductors oi a pair being small enough to the currents in theconductors he to neutralize their relative magnetic but the spacingbeing large enough to pro ti o adequate relative insulated clearance between the conductors of the pair, the spacing hethe being large enoughto provide at spate heat dissipation the pairs and isfactory accessbetween the pairs for tools hands and fasteners used in joining andsupthe conductors, the spacing between s losing considerably greaterthan the spacing r en or" a pair, and a casing surth conductors andhaving wide thin he adiating surfaces close to and parallel to Lea theside surfaces of the conductor.

6. In e. gzolzrphase distribution system, a source at pols phasealternating current, a plurality of wide thin conductors connectedthereto and arranged in remotely spaced definite and distinct pairs,each pair comprising two evenly and closely spaced conductors ofdifferent phases, arranged wide. face near wide face, each phasecomprising two conductors of different pairs, the relative arrangementof and the spacing between the two conductors of a pair being smallenough to permit the currents in the conductors of the pair toneutralize their relative magnetic effects but the spacing being largeenough to provide adequate relative insulated clearance between theconductors of the pairs, the spacing between the pairs being largeenough to provide adequate heat dissipation from the pairs andsatisfactory,

7 of polyphase alternating current, a plurality of wide thin conductorsconnected thereto and arranged in remotely spaced definite and distinctpairs, each pair comprising two evenly and closely spaced conductors ofdifferent phases, arranged wide face near wide face, each phasecomprising two conductors of different pairs, the relative arrangementof and the spacing between the two conductors of a pair being smallenough to permit the currents in the conductors of the pair toneutralize their relative magnetic effects but the spacing being largeenough to provide adequate relative insulated clearance between the tworows, each row comprising a conductor from each of the phases, each pairincluding a conductor from each of the rows, with the conductors facesclose to and parallel conductors of the pair, the spacing between thepairs being large enough to provide adequate heat dissipation from thepairs and satisfactory access between the pairs for toolsand hands andfasteners used in joining and supporting the conductors, the spacingbetween pairsbeing considerably greater than the spacing betweenconductors of a pair, the several conductors being arranged in two rows,each row comprising a conductor from each of the phases, each pairincluding a conductor from each of the rows, with the conductors of onerow directly above those of the other, and a casing surrounding theconductors and having wide thin heat radiating surfaces close to andparallel to the wide surfaces of the conductors.

8. In a polyphase distribution system, a source of polyphase alternatingcurrent, a plurality of wide thin conductors connected theretoandarranged in remotely spaced definite and distinct pairs, each paircomprising two evenly and closely spaced conductors of different phases,arranged wide face near wide face, each phase comprising two conductorsof different pairs, the relative arrangement of and the spacing betweenthe two conductors of a pair being small enough topermit the currents inthe conductors of the pair to neutralize their relative magnetic effectsbut the spacing being large enough to provide adequate relativeinsulated clearance between the conductors of the pair, the spacingbetween the pairs being large enough to provide adequate heatdissipation from the pairs and satisfactory access between the pairs fortools and hands and fasteners used in joining and supporting theconductors, the spacing between pairs being considerably greater thanthe spacing between conductors of a pair, the several conductors beingarranged in pairs, each pair comprising two evenly and close- 1y spacedconductors of different phases, arranged wide face near wide face, eachphase comprising two conductors of different pairs, the relativearrangement of and the spacing between the two conductors of a pairbeing small enough to permit the currents in the conductors of the pairto neutralize their relative magnetic effects but the spacing beinglarge enough to provide adequate relative insulated clearance betweenthe conductors of the pair, the spacing between the pairs being largeenough to provide adequate heat dissipation from the pairs andsatisfactory access between the pairs for tools and hands and fastenersused in joining and supporting the conductors, the spacing between pairsbeing considerably greater than the spacing between conductors of apair, each pair carrying current in substantially equal amounts and ofopposite directions, thus comprising a single phase transmission means,and a casing surrounding the conductors and having wide thin heatradiating surfaces close to and parallel to the wide surfaces of theconductors.

10. In a polyphase distribution system, a source of polyphasealternating current, a plurality of wide thin conductors connectedthereto and arranged in remotely spaced definite and distinct pairs,each pair comprising two evenly and closely spaced conductors ofdifferent phases, arranged wide face near wide face, each phasecomprising two conductors of different pairs, the

the two conductors of a pair being small enough to permit the currentsin the conductors of the pair to neutralize their relative magneticeffects but the spacing being large enough to provide adequate relativeinsulated clearance between the conductors of the pair, the spacingbetween the pairs being large enough to-provlde adequate heatdissipation from the pairs and satisfactory access between the pairs fortools and hands and fasteners used in joining and supporting theconductors, the spacing between pairs being considerably greater thanthe spacing between conductors of a pair, each conductor being a flatbar, and a casing surrounding the conductors and having wide thin heatradiating surfaces close to and parallel to the wide surfaces of theconductors.

11. In a polyphase distribution system, a source of polyphasealternating current, a plurality of wide thin conductors connectedthereto and arranged in remotely spaced definite and distinct pairs,each pair comprising two evenly and closely spaced conductors ofdifferent phases,

arranged wide face near wide face, each phase ductors connected but thespacing being large enough to provide adequate relative insulatedclearance between the conductors of the pair, the spacing between thepairs being large enough to provide adequate heat dissipation from thepairs and satisfactory access between the pairs for tools and hands andfasteners used in joining and supporting the conductors, the spacingbetween pairs being, considerably greater than the spacing betweenconductors of a pair, each pair carrying current in substantially equalamounts and of opposite directions, thus comprising a single phasetransmission means, each conductor being a flat bar, and a casingsurrounding the conductors and having wide thin heat radiating surfacesclose to and parallel to the wide surfaces of the conductors.

12. In a polyphase distribution system, a source 01 polyphasealternating current, a plurality of wide thin conductors connectedthereto and arranged in remotely spaced definite and distinct pairs,each pair comprising two evenly and closely spaced conductors ofdifferent phases, arranged wide face near wide face, each phasecomprising two conductors of diiIerent-pairs, the relative arrangementof and the spacing between the two conductors of a pair being smallenough to permit the currents in the conductors of the pair toneutralize their relative magnetic effects but the spacing being largeenough to provide adequate relative insulated clearance between theconductors of the pair, the spacing between the pairs being large enoughto provide adequate heat dissipation from the pairs and satisfactoryaccess between the pairs for tools and hands and fasteners used injoining and supporting the conductors, the spacing between pairs beingconsiderablly greater than the spacing between, conductors of a pair,the several conductors being arranged in two rows, each row comprising aconductor from each of the phases, each pair including a conductor fromeach of the rows, with the conductors of one row directly above those ofthe other, and a casing surrounding the conductors and having "wide thinheat radiating of and the spacing between pair being small enough topermit the magnetic field enects of the currents in the conductors ofthe pair to neutralize one another, but the spacing being large enoughto provide adequate relative insulated clearance between the conductorsof theh pair, the alternating current source being polyphase, with eachphase distributed over two pairs, there being as many pairs as phases,and a casing surrounding the conductors and having wide thin heatradiating surfaces close to and parallel to the wide surfaces of theconductors.

15. In a distribution system, a source of alternating current, aplurality of wide thin conductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs,

relative arrangement the two conductors of a each pair comprising twoevenly and closely surfaces clwe to and parallel to the wide surfacesrows of conductors so that each row of conductors may be mechanicallyassociated with a casing portion length.

13. In a distribution system, a source of al ternating current, aplurality of wide thin con ductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs, each paircomprising two evenly and closely spaced conductors carrying currents ofdifferent phases, arranged wide face near wide face, the relativearrangement of and the spacing between the two conductors of a pairbeing small enough to permit the magnetic ileld en'ects of the currentsin the between the conductors of the pair, and a casing surrounding theconductors and having wide thin heat radiating surfaces close to andparallel to the wide surfaces, of the conductors.

14.;[n a distribution system, a source of a1- ternating current, aplurality of wide thin conthereto and arranged in a pattern of aplurality oi definite and distinct pairs, each pair comp two evenly andclosely spaced conductors carrying currents of dinerent phases, arrangedwide race near wide face, the

spaced conductors carrying currents of different phases, arranged wideface near' wide face, the relative arrangement of and the spacingbetween the two conductors of a pair being small enough to permit themagnetic field eifects of the currents in the conductors of the pair toneutralize one another, but the spacing being large enough to provideadequate relative insulated clearance between the conductors of thepair, the pairs being remotely spaced whereby there is a minimum ofinterpai'r magnetic effects, with each conductor being adjacent no otherthan the mate of its pair, and a casing surrounding the conductors andhaving wide thinheat radiating surfaces close to and parallel to thewide surfaces of the conductors.

16. In a distribution system, a source of alternating current, aplurality of wide thin conductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs, each pairccmpiising two evenly and closely spaced conductors carrying currents ofdifierent phases, arranged wide face near wide face, the relativearrangement of and the spacing between the two conductors of a pairbeing small enough to permit the magnetic field effects of the currentsin the conductors of the pair to neutralize one another, but the spacingbeing large enough to provide adequate relative insulated clearancebetween the conductors of the pair, the alternating current source beingpolyphase, with each phase distributed over two pairs, therebeing asmany pairs as phases, the pairs being remotely spaced whereby there is aminimum of interpair magnetic effects, with each conductor beingadjacent no other than the mate of its pair, and a casing surroundingthe conductors and having wide thin heat radiating surfaces close to andparallel to the wide surfaces of the conductors.

of polyphase alternating current, a plurality of thereto and arpairsbeing large enough dissipation from the to provide adequate heat pairsand satisfactory access enough to provide heat dissipation from tenersused in joining and supporting the conductors, the spacing between pairsbeing considranged in remotely spaced definite and distinct pairs, eachpair comprising two evenly and closely spaced conductors of differentphases, arranged wide face near wide face, each phase comprising twoconductors of different pairs, the relative arrangement of and thespacing between the two conductors of a pair being small enough topermit the currents in the conductors of the pair to neutralize theirrelative magnetic effects but the spacing being large enough to provideadequate relative insulated clearance between the conductors of thepairs, the spacing between the pairs being large enough to provideadequate heat dissipation from the pairs and satisfactory accessbetweenthe pairs for tools and hands and fasteners used in joining andsupporting the conductors, the spacing between pairs being considerablygreaterthan the spacing between conductors ofa" pair, the severalconductors being arranged in two groups, each group comprising aconductor from'each of the phases, each pair including a conductor fromeach of the groups.

19. In a polyphase distribution system, a

' source of polyphase alternating current, a plurality of wide thinconductors connected thereto and arranged in remotely spaced definiteand distinct pairs, each pair comprising two evenly and closely spacedconductors of different phases, arranged wide face near wide face, eachphase comprising two conductors of different pairs, the relativearrangement of and the spacing between the two conductors of a pairbeing vsmallenough to permit the currents'in the conductors of the pairto neutralize their relative magnetic effects but the spacing beinglarge adequate relative insulated clearance between the conductors ofthe pair, the spacing between the pairs being large enough to provideadequate heat dissipation from the pairs and satisfactory access toolsandhands and fasteners used in joining and supporting the conductors,thespacing between pairs being considerably greater than the spacingbetween conductors of a pair, the several conductors being arranged intwo rows, each row comprising a conductor from each of the phases, eachpair including a conductor from each of the rows, with the conductors ofone row directly above those of the other.

20. In a polyphase distribution system, a source of polyphasealternating current, a pluto and arranged in remotely spaced definiteand distinct pairs, each pair comprising two evenly and closely spacedarranged wide face, near wide face, each phase comprising two conductorsof different pairs, the relative arrangement of and the spacing betweenthe two conductors of a pair being small enough to permit the currentsin the conductors of the pair to neutralize'their relative magneticeffects but the spacing being large enough to provide adequate relativeinsulated clearance between the conductors of the pair, the spacingbetween the pairs being large enough to provide adequate the pairs andsatisfactory access between the pairs for tools andhands and fastenersused in joining and supporting the between the pairs for clearancebetween conductors of different phases,

- arranged wide face near wide face,

conductors, the spacing between pairs being considerably greater thanthe spacing between con ductors of a pair, the several conductors beingarranged in two rows, each row comprising a conductor from each of thephases, each pair including a conductor from each of the rows, with theconductors of one row directly above those of the other, and aninsulation barrier between the two rows of conductors.

21. In a polyphase distribution system, a source of polyphasealternating current, a plurality of wide thin conductors connectedthereto and ar-' definite and distinct two evenlyand close- I ranged inremotely spaced pairs, each pair comprising 1y spaced conductors ofdifferent phases, ar-

ranged wide face near wide face, each phasecomprising two conductors ofdifferent pairs, the.

relative arrangement of and the spacing between the two conductors of apair being small enough to permit the currents in pair to neutralizetheir relative magnetic effects but the spacing being large enough toprovide adequate relative insulated clearance between the conductors ofthe pair, the spacing between the pairs being large enoughto provideadequate heat dissipation from the pairs and satisfactory access betweenthe pairs for tools and hands and fasteners used in joining andsupporting the conspacing between pairs being considerably greater thanthe spacing between conductors of a pair, each pair carrying current insubstantially equal amounts and of opposite directions, thus comprisinga single phase transmission means.

22. In a polyphase distribution system, a source of polyphasealternating current, a plurality of wide thin conductors-connectedthereto and arranged in remotely spaced definite and distinct pairs,each pair comprising two evenly and closely spaced conductors ofdifferent phases, arranged wide face near wide face, each phasecomprising two conductors of different pairs, the relative arrangementof and the spacing between the two conductors of a pair being smallenough to permit the currents in the conductors of the pair toneutralize their relative magnetic effects but enough to provideadequate relative insulated the conductors of the pair, the spacingbetween the pairs being large enough to provide adequate heatdissipation from the ductors, the

pairs and satisfactory access between the pairs betweenpairs beingconsiderably greater than the spacing between conductors of a pair, eachconductor being a flat bar.

23. In a polyphase distribution system, a

source of polyphase alternating current, a p1u-' rality of wide thinconductors connected thereto and arranged in remotely spaced definiteand distinct pairs, each pair comprising, two evenly and closely spacedconductors of different phases, each phase comprising two conductors ofdifferent pairs, the

, relative arrangement of and the spacing between the two conductors ofa pair being small enough to permit the currents in the conductors ofthe pair to neutralize their relative ,magn'etic effects but the spacingbeing large enough to provide adequate relative insulated clearancebetween the conductors of the pair, the spacing between the pairs beinglarge enough to provide adequate heat dissipation from the pairs andsatisfactory and hands and access between the pairs for tools theconductors of, the

the spacing. being large fasteners used in joining and supporting theconductors, the spacing between pairs being considerably greater thanthe spacing between conductors or a pair, each pair carrying current insubstantially equal amounts and 01' opposite directions, thus comprisinga single phase transmission means, each conductor being a flat'bar.

24. In a distribution system, a source of alternating current, aplurality of wide thin conductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs, each paircomprising two evenly and closely spaced conductors carrying'currents ofdifferent phases, arranged wide i'ace near wide face, the relativearrangement of and the spacing between the two conductors of a pairbeing small enough to permit the magnetic field efiects of the currentsin the conductors of the pair to neutralize one another, but the spacingbeing large enough to provide adequate relative insulated clearancebetween the conductors of the pair.

25. In a distribution system, a source of alternating current, aplurality of wide thin conductors connected thereto'and arranged in apattern of a plurality oi definite and distinct pairs, each paircomprising two evenly and closely spaced conductors carrying currents ofdifferent phases, arranged wide face near wide face, the relativearrangement or and the spacing between the two conductors of a pairbeing small enough to permit the magnetic field effects of the currentsin the conductors of the pair to neutralize one another, but the spacingbeing large enough to provide adequate relative insulated clearancebetween the conductors' of the pair, the alternating current sourcebeing polyphase, with each phase distributed over two pairs, there beingas many pairs as phases.

26. In a distribution system, a source of alterhating current, aplurality of wide thin conductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs, each paircomprising two evenly and closely spaced onductors carrying currents ofdiiterent phases, arranged widetace near wide face, the relativearrangeemnt 01' and the spacing between the two conductors oi a pairbeing small enough to permit the magnetic field efl'ects oi' thecurrents in the conductors of the pair to neutralize one another, butthe spacing being large enough to provide adequate relative insulatedclearance between the conductors of the pair, the pairs being remotelyspaced whereby there isa minimum of interpair magnetic efiects, witheach conductor being adjacent no other than the mate of its pair.

27. In a distribution system, a source of alternating current, aplurality of wide thin conductors connected thereto and arranged in apattern of a plurality of definite and distinct pairs, each paircomprising .two evenly and closely spaced conductors carrying currentsof diirerent phases, arranged wide face near wide face, the relativearrangement of and the spacing between the .two conductors of a pairbeing small enough to permit the magnetic field efiects of the currentsin the conductors of the pair to neutralize one another, but the spacingbeing large enough to provide adequate relative insulated clearancebetween the conductors of the pair, the alternating current source beingpo yphase, with each phase distributed over two pairs, there being asmany pairs as phases, the pairs being remotely spaced whereby there is aminimum oi interpair magnetic efiects, with each conductor beingadjacent no other than the mate 01' its pair.

28. A construction of the character specified in claim 84, wherein thearrangement of the pairs is such that neutralization within a pair isnot impaired by any other pair or the system.

29. A construction of the character specified in claim 24, wherein eachconductor bounds a clear space large enough to provide adequate heatdissipation from it and from an adjacent conductor which also boundsthat space with the space being large enough, where the conductors arejoined and fastened, to provide satisfactory access to the twoconductors bounding that space for tools and fasteners used in Joiningand supporting the conductors.

80. A construction of the character specified in claim 24, wherein thearrangement of the pairs is such that neutmlimtion within a pair is notimpaired by any othe pair of the system, and wherein each conduc rbounds a clear space large enough to provide adequate heat dissi ationfrom it and from an adjacent conductor whichalsobounds thatmacewiththespacebeing large nough, where the conductors are joined andfastened, to provide satisfactory access to the two conductors for toolsand fasteners used in porting the conductors.

31. A construction oi the character specified in claim 25, whereinthelrrangunent or thepairs is such that neutralization within a pair isnot impaired by any other pair or the ustem.

ALVA A. 'IOGISIN. LAWRINCI I. FISHER.

